1. Field of the Invention
The present general inventive concept relates to an inkjet print head and a method of manufacturing the same. More particularly, the present general inventive concept relates to a MEMS (Micro Electro Mechanical System) device and a method of manufacturing the same, capable of forming a chamber layer having a uniform thickness.
2. Description of the Related Art
In general, an ink jet print head discharges fine droplets of a printing ink on a required position of a record paper, thereby printing an image having a predetermined color. The ink jet print head includes a thermal driving type ink jet print head, in which a heater is installed in the print head to form bubbles by using a heat generated from the heater and the ink droplets are sprayed due to a pressure of the bubbles.
The thermal driving type ink jet print head includes a substrate, on which a plurality of substance layers including a plurality of heaters for heating the ink are stacked, a chamber layer formed on the substrate to provide a channel and an ink chamber on the substrate, and a nozzle layer, which is formed on the chamber layer and has a nozzle corresponding to the ink chamber.
The nozzle layer has been stacked on an upper surface of the chamber layer as described above. Before the nozzle layer is stacked on the chamber layer, a sacrificial layer is stacked on the chamber layer, the sacrificial layer is planarized through a CMP (Chemical Mechanical Polishing) process, and an inspection is performed to determine whether the chamber layer has a required thickness through the planarization process.
Meanwhile, in the process of planarizing the MEMS device through the CMP process, the sacrificial layer stacked on the chamber layer is primarily planarized, and then the sacrificial layer stacked on the ink chamber of the chamber layer and the chamber layer are simultaneously planarized, thereby controlling a final thickness of the chamber layer.
In this case, if the process of planarizing the MEMS device through the CMP process is insufficiently performed, an upper surface of the chamber layer is not exposed. Thus, when the sacrificial layer is removed, the nozzle layer is not completely bonded to the chamber layer, so that delamination may occur between the above two layers. Further, if the process of planarizing the MEMS device through the CMP process is excessively performed, a thickness of the chamber layer is reduced as compared with an original thickness thereof, so that a volume of the ink droplet is changed, thereby degrading the printing quality.
That is, the process of planarizing the MEMS device through the CMP process must be completed when the chamber layer has a proper thickness. To this end, after the planarization process through the CMP process has been completed, an inspection is performed using an inspection device, such as an optical microscope, to determine if the MEMS device is properly planarized.
However, in the conventional MEMS device, a thickness inspection for the chamber layer using the inspection device such as the optical microscope is performed by calculating a total thickness of the substrate and the chamber layer stacked on the substrate, and then subtracting a thickness of the substrate from the total thickness.
Therefore, according to the related art, a precise inspection on the thickness of the chamber layer is not easy due to irregularity of the substrate on which the chamber layer is stacked, so that a precise inspection such as a destructive inspection must be performed after the MEMS device has been manufactured.